Online Calculators & Tools
Free calculators, converters, and tools for math, finance, health, web development, and everyday tasks. Fast, accurate, and mobile-friendly.
Categories
Math
Percentage, average, ratio, standard deviation, fraction, area, and scientific calculators.
7 toolsFinance
Mortgage, loan, interest, retirement, savings, tip, sales tax, and percentage change calculators.
17 toolsHealth
BMI, age, calorie, and ideal weight calculators.
6 toolsWeb Development
HTML escape, URL encode, Base64, JSON formatter, and word counter.
8 toolsConverters
Length, weight, temperature, speed, time, volume, and data storage unit converters.
8 toolsEveryday
Password generator, random number, dice roller, coin flip, date calculator, date diff, and number to words.
15 toolsPopular Tools
Grade Calculator
Calculate weighted grades, final exam scores needed, and overall course averages.
EverydayGPA Calculator
Calculate your GPA on a 4.0 scale, 5.0 scale, or custom scale. Supports weighted and unweighted.
EverydayHourly to Salary Calculator
Convert hourly wage to annual, monthly, and weekly salary. Includes overtime and part-time options.
FinanceSalary to Hourly Calculator
Convert annual salary to hourly wage. See how much you earn per hour, week, and month.
FinanceHours Calculator
Calculate hours and minutes between two times. Perfect for work shifts, timesheets, and time tracking.
EverydayPaycheck Calculator
Calculate net pay, gross pay, and deductions. Estimate your take-home pay after taxes.
FinanceInflation Calculator
Calculate inflation-adjusted value, purchasing power, and average inflation rate between years.
FinancePercentage Calculator
Calculate percentages, find what percent a number is of another, and percentage change.
MathFraction Calculator
Add, subtract, multiply, divide, and simplify fractions with step-by-step results.
MathBMI Calculator
Calculate Body Mass Index with metric or imperial units and health categories.
HealthLoan Calculator
Calculate monthly payments, total interest, and amortization schedule.
FinanceTip Calculator
Calculate tip amount and split bills easily between multiple people.
FinanceTemperature Converter
Convert between Celsius, Fahrenheit, and Kelvin instantly.
ConvertersPassword Generator
Generate secure random passwords with custom length and symbols.
EverydayCompound Interest Calculator
Calculate compound interest with contributions and see growth over time.
FinanceJSON Formatter & Validator
Format, validate, and pretty-print JSON data.
Web DevelopmentDate Difference Calculator
Calculate days, weeks, months, and years between two dates.
EverydayMortgage Calculator
Calculate monthly mortgage payments, total interest, and amortization schedule with down payment.
FinanceAmortization Calculator
Generate a full loan amortization schedule showing principal, interest, and balance breakdown for every payment.
FinanceSavings Calculator
Calculate savings growth with regular contributions, interest rates, and time horizons.
FinanceDate Calculator
Add or subtract days, weeks, months, or years from any date. Find future and past dates instantly.
EverydayRetirement Calculator
Plan your retirement savings with contribution growth, Social Security, and withdrawal estimates.
FinanceTime Calculator
Add and subtract time values, convert between hours, minutes, seconds, and decimal time.
ConvertersScientific Calculator
Advanced calculator with trigonometry, logarithms, exponents, factorial, and constants.
MathDiscount Calculator
Calculate sale price, discount amount, and final cost after percentage or fixed discounts.
FinanceProfit Margin Calculator
Calculate gross profit, net profit, markup percentage, and profit margins for any product or service.
FinanceOvulation Calculator
Predict your fertile window, ovulation date, and next period based on your cycle length.
HealthDue Date Calculator
Estimate your baby due date using last menstrual period, conception date, or IVF transfer date.
HealthCurrency Converter
Convert between 50+ currencies with live exchange rates from central banks. Fast, accurate, and free.
ConvertersData Storage Converter
Convert between bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes instantly.
ConvertersHex to Decimal Converter
Convert hexadecimal numbers to decimal, binary, and octal. Supports signed and unsigned values.
Web DevelopmentBinary Calculator
Add, subtract, multiply, and divide binary numbers. Convert between binary, decimal, and hex.
Web DevelopmentSubnet Calculator
Calculate IP subnets, CIDR ranges, network addresses, broadcast addresses, and host counts.
Web DevelopmentDebt to Income Calculator
Calculate your debt-to-income ratio to see if you qualify for a mortgage or loan. Compare front-end and back-end DTI.
FinanceRent Calculator
Calculate how much rent you can afford using the 30% rule, 50/30/20 budget, and income-based methods. Compare rent-to-income ratios.
FinanceSquare Footage Calculator
Calculate square footage for rooms, houses, flooring, and land. Supports rectangle, circle, triangle, and trapezoid shapes with unit conversion.
EverydayHow Long Until
Count down the exact time until any future date or event. Live updating countdown with years, months, days, hours, minutes, and seconds.
EverydayHow Long Ago
See exactly how much time has passed since any past date or event. Live updating with years, months, days, hours, minutes, and seconds.
EverydayDate Add Calculator
Add any number of days to a date and see the result instantly. Perfect for deadlines, contracts, and planning.
EverydayBusiness Days Calculator
Add business days to any date, automatically skipping weekends. Essential for HR, payroll, and project deadlines.
EverydayAll Calculators
💰 Finance
Why Use Our Calculators?
Instant Results
All calculations run directly in your browser. No server delays, no page reloads.
Mobile Friendly
Every tool is optimized for phones, tablets, and desktops with responsive design.
Private & Secure
Your data never leaves your device. No tracking, no cookies, no data collection.
Educational
Learn the formulas, see examples, and understand how each calculation works.
SEO Optimized
Every page includes structured data, Open Graph tags, and XML sitemap support.
100% Free
No registration required. No ads. Just fast, free tools that work every time.
Frequently Asked Questions
Are all calculators free to use?
Yes, every calculator on SumItUp is completely free. No registration, no ads, no hidden fees.
Do the calculators work on mobile phones?
Absolutely. All tools are built with a mobile-first responsive design and work perfectly on any device.
Is my data safe when using these tools?
Yes. All calculations happen inside your browser. We never send your data to any server.
Can I use these calculators offline?
Once a page is loaded, most calculators work without an internet connection.
How accurate are the results?
Our calculators use standard mathematical formulas and provide results accurate to multiple decimal places.